This invention relates to an apparatus for converting fluid motion into another form of energy, in general, and to a fluid powered motor-generator apparatus in particular.
Many devices are known for utilizing the energy of moving fluid to generate mechanical or electrical energy. For example, a windmill converts the energy in the wind to mechanical energy by driving a pump or to electrical energy by driving a generator. A water wheel converts the energy in moving water to mechanical or electrical energy in much the same manner as the windmill.
One source of energy is the current flow in a sea or a river. U.S. Pat. No. 2,501,696 discloses a stream turbine which includes a streamlined casing containing gears and a generator driven by an external propeller. A pair of such devices are mounted on a wing with the propellers running in opposite directions. The structure is buoyant and is anchored in a waterway. However, the diameter of the propellers, and thus the generating capacity, is limited by the depth of the waterway.
U.S. Pat. No. 3,922,012 discloses a submersible power generator for use in oceans and rivers. The generator has rotor with a plurality of horizontally radiating spokes mounted in common on a rotatable vertical shaft to drive the same. Each spoke has a hinged impeller blade by which its automatic positioning relative to its spoke maximizes the surface area of the blade acted on by the water current through a part of the rotor displacement and minimizes such surface area through other parts of the displacement, thereby producing the necessary asymmetrical force required to generate rotation.
U.S. Pat. No. 4,045,148 discloses a turbine with a water-driven motive element immersed in a body of water. The motive element includes a disc having a density close to that of water and horizontally disposed with a plurality of cells containing a mixture of liquid and gas. The disc carries on the upper and lower surfaces thereof a plurality of blades which are pivotably movable about a horizontal axis. The blades each have at least one pocket containing a mixture of gas and liquid such that the density of the blades connected to the upper surface of the disc is less than that of water and the density of the blades connected to the lower surface of the disc is greater than that of water. The disc also has a structure which holds the blades in one direction of pivotal movement when the blades reach a vertical position. As a consequence, under the action of water current, the blades are driven to their vertical position and they then effect rotation of the disc which drives an electrical generator system.
U.S. Pat. No. 4,095,422 discloses a vertical-axis composite swinging-blade water wheel for converting the kinetic energy of a substantially horizontal stream of fluid into mechanical energy. Pairs of blade wheels are disposed symmetrically with respect to an output shaft to prevent the composite water wheel from rotating. A plurality of the blade wheels are arranged vertically on the water wheel shaft so that each two adjacent blade wheels deviate from each other through a predetermined angle to prevent inner currents of water between the blades and equalize the fluctuations of the driving torques, thereby improving the efficiency and securing a relatively large power output.
U.S. Pat. No. 4,262,211 discloses a liquid storage device and energy generator including a plurality of floating, elongate, liquid storage containers arranged in circular fashion for rotation about a centrally positioned generator. The containers may be floated in relatively shallow waters which move at differential speeds to cause the entire pattern of storage containers to rotate and produce electrical energy.